But three months after the fee notices were mailed, a large number of property owners remain delinquent on what they owe. According to figures presented during a council workshop Tuesday night, the city has collected just 64 percent of the fees that are owed, leaving a shortfall of $138,328.

City officials now have to decide how hard they want to lean on delinquent property owners to get the remaining amount. Council members discussed several options before deciding to send a second letter to the delinquent offenders, along with a warning that a penalty will be added if the fees are not paid by June 1.

"We can't let it go too long or we'll end up losing money," said Mayor Lara Bradburn, who worried that the city will have a difficult time collecting the money if it waits and tacks the unpaid fees onto property owners' 2013-14 tax bills.

Although council members didn't take action Tuesday, they agreed on the idea of adding the 10 percent penalty to any assessment that isn't paid by the June 1 deadline.

Although adopted last June by the City Council, the new two-tiered assessment could not be implemented until it was validated in Circuit Court. By the time the validation period passed, it was too late to add the fees to the 2012-13 property tax notices sent out by the county Tax Collector's Office. In November, the city mailed assessment notices to 3,950 property owners, who had until Jan. 15 to pay the fees before they became delinquent.

Council member Frankie Burnett speculated that because of the newness of the assessment, some property owners, especially those who aren't residents of the city, might not have been aware that they owed the fees.

"Those bills didn't go out until November, and maybe some people just didn't pay attention to them," said Burnett. "They probably just need a little extra reminder."

The assessment will be reviewed annually by the council. The 2012-13 rate included a $71 flat fee, plus 52 cents per $1,000 of improvements on parcels, with the exception of religious establishments and nonprofit organizations. A property owner with $100,000 worth of improvements was assessed $52 on the improvements, plus the $71 flat fee, for a total of $123.

Starting this year, the annual city assessment will be included on county-issued property tax bills.